Improvement in sewing-machines



T. J. w. ROBERTSON.

5 W Sewing Macihne. No. 12,577. Patented March 20, I855.

N. PKTERS, Phowlimognphw, Washinginn. D. C-

g V v UNITED r STATES,

PATENT OFFIQE.

v r. J. w; nonnarson, on NEW. YORK, N. Y.,' Assionoa 'ro HIMSELF AND A.E. BEACH. I

iMPROVEMENT |N SEWING-MACHINES.

Specificationforming part of Letters Patent No. 2,577, dated March 20,1855.

' To all whom it may concern:

Be it known that ;I, T. J. W. ROBERTSON, of the city, county, and Stateof New York, have invented a new anduseful Improvement in theFeed-Motion of Sewing-Machines; and I do hereby declare that thefollowing is a a full, clear, and exact description of the same, areference being had to the accompanying drawingsyforming part of thisspecification, in which- Figure 1 is a front view of a portion of asewing-machine with inyimproved feed-motion applied. Fig. 2 is a plan ofthe same. Similar letters of reference indicate corresponding parts inboth figures.

To enable those skilled in the art to make and-use my invention, I willproceed to describe its construction andoperation.

A. in the accompanying drawings is the cloth-table. B is theneedle-slider, and O O the slide in which the said slider works. Theseparts. are all arranged in the same way as the corresponding parts ofmanywell-known sewing-machines.

D is a spring of the form I propose gener;

ally to employ to confine the cloth to the table. This spring consistsof a curved bar of steel attached to theside of the slider O O, or otherfixed portion of the machine, and terminating with a broad shoe, E, tobear upon the mate-. rial to be sewed all round the needle, the latterbeing intended to workthrough the opening a, (see Fig. 2,) made in theshoe for the purpose. Another hole, I), is also .made in the shoe forthe feedingdog to work through. The blue line in Fig. 1 represents thematerial confined to the table by the spring.

f is the feeding-dog, consisting of a piece of steel or other metalhaving a serrated face, and being attached rigidly to or forming part ofa light bar, F, which is suspended from the arm c of a three-armed leverwhose fulcrum is a pin, d,which may be either secured in the upper partof the spring D, as represented, or in I some other convenient fixedpart of the machine. If the said bar is attached'to the spring D, allthe elasticity should be belowthe point of such attachment. The dogworksthrough the opening bin the shoe E, which should be At about asnear as possible to the needle. the middle of its length the bed-bar Fworks within aforked guide, 6, attached to the spring D, and near thisguide an adjusting'screw, 9,

(see Fig. 1,) is fitted to the spring D, (which will be pushed asideduring the ascent of the needle and the latter during the descent of theneedle by a wiper. j, attached to the needle-slider B. The effect of thelatter movement is to raise the arm 0, to which the feedbar is attached,and of the former to depress the said arm.

I will now describe the feeding operation,

first supposing the dog to be raised from the surface of thecloth andhanging against the screw 9, as indicatedin red outline in Fig.

l. I will now suppose the needle-slider and the wiper to be rising fromthe cloth, by which action the wiper j will push aside the arm h of thethree-armed lever tothe position in which it is shown in black outline,and in so doing will depress the arm 0. The feed-bar F, during the aboveoperation, will slide along the point of the screw 9 until the dog fbears upon the cloth, after which the dog will be caused to slide thecloth along the table in the direction of the arrow. WVhen theneedleslider and wiper j descend, the wiper in pushing aside the arm twill raise the arm 0, and, as the dog is by that means withdrawn fromcontact with the cloth, the feed-bar will fall back to the screw g.

The screw 9 serves to regulate the length of stitch by controlling thebackward movement of the dog; or the length of stitch may be varied bymoving the wiper farther in or out to move the dog farther or not so farforward.

In applying the feed-bar care must be taken ing the perpendicular toprevent the dog slid ing easily. I consider an angle of about twentydegrees to be well adapted for the purpose.

In order to prevent a reaction being produced on the dog by anyelasticity of the cloth or material being sewed, after the wiperj passesthe arm 7 in its upward motion, I attach a spring, k, to the fixed partof the machine, so as to produce friction upon the pin 8, by which I thefeed-bar is connected to the arm c of the three-armed lever, or applysome equivalent device to produce sufficient friction on the said pin toprevent the dog being returned by such means.

I have only represented a single toothed feeding-dog5 but I propose touse two united in the form of a fork, one working on one side and theother on the other side of the needle,

which will work within the fork.

Most of the feed-motions now in common use, with a spring to hold orconfine the mamotions the dog is arranged under the table and actsagainst the spring or plate E. If there is any extra resistance to thefeeding of the cloth, the spring or shoe is apt to give or rise, andconsequently the dog will not act properly upon the cloth. By arrangingthe dog on the upper side of the cloth, so that it will act against arigid plate or table, this (10- feet is avoided, and the advantage ofthe yielding pressure of the springE upon the cloth is retained. Thereis another advantage in arranging the feeding-dog on the upper side ofthe table. It gives room and opportunity for forming a forked dog, sothat'the needle may work between the forks of the dog, instead of on oneside, as heretofore.

I do not claim in itself as new the arrangement of the feeding-dog andspring-clamp separately operating upon the cloth on its one or outsidesurface, as such. has before been done by the alternate action of thesedevices. Neither do I claim of itself a separate and constantspring-pressure applied to the outside surface of the cloth when thefeeding bar or dog is otherwise arranged to operate in connection withthe spring clamp or hold, as specified; but

I do claim as new and useful and desire to Secure by Letters Patent Thecombination of the spring-clamp D with the feeding bar or dog f,constructed, arranged, and operating together against the cloth on itsone side or surface substantially as set forth.

T. J. W. ROBERTSON.

\Vi tnesses WM. DIXEY, A. E. BEACH,

